My 2005 Nissan Micra (petrol) has been very slow to start from cold recently. It does start first time, but is sluggish until the ignition "kicks in" and turns over in a slow, less positive manner.

I drive about 3000 miles a year and do occasional long distance journeys. The battery was changed in February this year and the starter motor and ignition barrel were changed in 2007 following a vehicle break down. The oil was changed to 5w 30 this February from 10 w 40 previously. Any ideas regarding the slow start, as it is normally so reliable.